Wine over 40 years old bottled in screw cap has been professionally tasted (and found superior to the cork equivalent). Do you really think 50 year old wine is needed before the jury can be in I personally own 1990 wine in screw cap (so that is 20 years old now) and am a convert though I confess to hating the thought of screw caps when I first saw them. Corks have theatre, but it is false snobbism and the technical advantage is too compelling for screw caps.

Almost all high-end wines in screw caps are also bottled in cork -- restaurants demand cork. Most distributors can't be bothered with stocking the same wine in 2 different closures. Most of the Grant Bruge in my cellar is in screw caps (in fact I had one last night with dinner, fwiw).